On Thu, Nov 17, 2022 at 01:15:11AM +0100, Stefano Brivio wrote:On Wed, 16 Nov 2022 15:42:06 +1100 David Gibson <david(a)gibson.dropbear.id.au> wrote:FixedThis bit in the TCP specific epoll reference indicates whether the connection is IPv6 or IPv4. However the sites which refer to it are already calling accept() which (optionally) returns an address for the remote end of the connection. We can use the sa_family field in that address to determine the connection type independent of the epoll reference. This does have a cost: for the spliced case, it means we now need to get that address from accept() which introduces an extran copy_to_user(). However, in future we want to allow handling IPv4 connectons through IPv6 sockets, which means we won't be able to determine the IP version at the time we create the listening socket and epoll reference. So, at some point we'll have to pay this cost anyway. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- tcp.c | 10 ++++------ tcp.h | 2 -- tcp_splice.c | 9 ++++----- 3 files changed, 8 insertions(+), 13 deletions(-) diff --git a/tcp.c b/tcp.c index 0513b3b..b05ed6c 100644 --- a/tcp.c +++ b/tcp.c @@ -662,8 +662,7 @@ static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn) { int m = conn->c.in_epoll ? EPOLL_CTL_MOD : EPOLL_CTL_ADD; union epoll_ref ref = { .r.proto = IPPROTO_TCP, .r.s = conn->sock, - .r.p.tcp.tcp.index = CONN_IDX(conn), - .r.p.tcp.tcp.v6 = CONN_V6(conn) }; + .r.p.tcp.tcp.index = CONN_IDX(conn) }; struct epoll_event ev = { .data.u64 = ref.u64 }; if (conn->events == CLOSED) { @@ -2745,7 +2744,7 @@ static void tcp_tap_conn_from_sock(struct ctx *c, union epoll_ref ref, conn->ws_to_tap = conn->ws_from_tap = 0; conn_event(c, conn, SOCK_ACCEPTED); - if (ref.r.p.tcp.tcp.v6) { + if (sa->sa_family == AF_INET6) { struct sockaddr_in6 sa6; memcpy(&sa6, sa, sizeof(sa6)); @@ -3019,8 +3018,7 @@ static void tcp_sock_init6(const struct ctx *c, in_port_t port) { in_port_t idx = port + c->tcp.fwd_in.delta[port]; - union tcp_epoll_ref tref = { .tcp.listen = 1, .tcp.v6 = 1, - .tcp.index = idx }; + union tcp_epoll_ref tref = { .tcp.listen = 1, .tcp.index = idx };Excess whitespace (from earlier patch).Fixed.int s; s = sock_l4(c, AF_INET6, IPPROTO_TCP, addr, ifname, port, tref.u32); @@ -3084,7 +3082,7 @@ static void tcp_ns_sock_init6(const struct ctx *c, in_port_t port) { in_port_t idx = port + c->tcp.fwd_out.delta[port]; union tcp_epoll_ref tref = { .tcp.listen = 1, .tcp.outbound = 1, - .tcp.v6 = 1, .tcp.index = idx}; + .tcp.index = idx};Missing whitespace (from earlier patch).Yes indeed, fixed.int s; assert(c->mode == MODE_PASTA); diff --git a/tcp.h b/tcp.h index a940682..739b451 100644 --- a/tcp.h +++ b/tcp.h @@ -33,7 +33,6 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s, * union tcp_epoll_ref - epoll reference portion for TCP connections * @listen: Set if this file descriptor is a listening socket * @outbound: Listening socket maps to outbound, spliced connection - * @v6: Set for IPv6 sockets or connections * @timer: Reference is a timerfd descriptor for connection * @index: Index of connection in table, or port for bound sockets * @u32: Opaque u32 value of reference @@ -42,7 +41,6 @@ union tcp_epoll_ref { struct { uint32_t listen:1, outbound:1, - v6:1, timer:1, index:20; } tcp; diff --git a/tcp_splice.c b/tcp_splice.c index 30ab0eb..7c2f667 100644 --- a/tcp_splice.c +++ b/tcp_splice.c @@ -167,11 +167,9 @@ static int tcp_splice_epoll_ctl(const struct ctx *c, { int m = conn->c.in_epoll ? EPOLL_CTL_MOD : EPOLL_CTL_ADD; union epoll_ref ref_a = { .r.proto = IPPROTO_TCP, .r.s = conn->a, - .r.p.tcp.tcp.index = CONN_IDX(conn), - .r.p.tcp.tcp.v6 = CONN_V6(conn) }; + .r.p.tcp.tcp.index = CONN_IDX(conn) }; union epoll_ref ref_b = { .r.proto = IPPROTO_TCP, .r.s = conn->b, - .r.p.tcp.tcp.index = CONN_IDX(conn), - .r.p.tcp.tcp.v6 = CONN_V6(conn) }; + .r.p.tcp.tcp.index = CONN_IDX(conn) }; struct epoll_event ev_a = { .data.u64 = ref_a.u64 }; struct epoll_event ev_b = { .data.u64 = ref_b.u64 }; uint32_t events_a, events_b; @@ -504,6 +502,7 @@ static void tcp_splice_dir(struct tcp_splice_conn *conn, int ref_sock, * tcp_splice_conn_from_sock() - Attempt to init state for a spliced connection * @c: Execution context * @ref: epoll reference of listening socket + * @ipv6: Should this be an IPv6 connection?Left-over from previous idea I guess.-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson* @conn: connection structure to initialize * @s: Accepted socket * @sa: Peer address of connection @@ -517,7 +516,7 @@ bool tcp_splice_conn_from_sock(struct ctx *c, union epoll_ref ref, { assert(c->mode == MODE_PASTA); - if (ref.r.p.tcp.tcp.v6) { + if (sa->sa_family == AF_INET6) { const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa; if (!IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))